Странно, ведь он блокирует дофамин
Разве блокирует? У него есть некоторое косвенное дофаминергическое действие, насколько я помню.
Цитата из Stahl's Essential Psychopharmacology:
"In order to understand how 5HT1A partial agonism can also reduce EPS, it is important to grasp how 5HT1A receptors function in various parts of the brain, and how they can regulate dopamine release in the striatum. Postsynaptic 5HT1A receptors in prefrontal cortex are accelerators for dopamine release in striatum. If 5HT2A stimulation is the “brake” stopping downstream dopamine release (Figure 5-15A), and 5HT2A antagonism“cuts the brake cable,” enhancing dopamine
release (Figure 5-15B), what is the accelerator for downstream dopamine release in the striatum? The answer is postsynaptic 5HT1A receptors on pyramidal neurons in the cortex (Figure 5-15C, box 1). 5HT1A receptor stimulation in the cortex hypothetically stimulates downstream dopamine release in the striatum, by reducing
glutamate release in the brainstem, which in turn fails to trigger the release of inhibitory GABA at dopamine neurons there (Figure 5-15C, box 2). Dopamine
neurons are thus disinhibited, just as they are by a 5HT2A antagonist. This would theoretically cause dopamine release in striatum, and mitigate EPS. Presynaptic 5HT1A receptors in raphe are also accelerators for dopamine release in the striatum"
Правда тут речь только про стриатум, что обуславливает отсутствие
ЭПС. Можете прочесть далее сами, это в Главе 5 про антипсихотики, страница 174.